The un-sunny side of Arizona was revealed at Senate hearings when Republican William Rehnquist was named to the Supreme Court in 1971.

Rehnquist denied allegations that he personally challenged minority voters at the polls. But he told the Senate he witnessed Republican poll challenges in 1962 that “struck me as amounting to harassment and intimidation.”

Stuff happened. And it wasn’t so long ago.

And now? Two of today’s most effective strategies to increase Latino voter participation are under attack in Arizona’s GOP-controlled Legislature.

One, Senate Bill 1261, provides a mechanism to purge voters from the permanent early voting list if they haven’t voted in the past two elections.

Daria Ovide is communications director for Central Arizonans for a Sustainable Economy. After helping in efforts to get tens of thousands of Latinos registered to vote, she says mail-in ballots appeal to minority voters because they eliminate any chance of being challenged at the polls.

The other bill, Senate Bill 1003, prohibits members of a community group or political organization from collecting and submitting early ballots.

“This could be pretty devastating” to voter turnout in rural communities, says David R. Berman, senior research fellow with Arizona State University’s Morrison Institute.

Ovide says, “Both bills target techniques that have been used since 2009 to increase Latino voter registration and turnout.”

Election-law changes may be necessary. Too many people had to cast provisional ballots in November because they were on the early voting list but showed up at the polls to vote instead of sending in their ballot.

But changes in election laws should be enlightened by history. All voters have not been treated the same, and all voters are not going to be affected equally by changes.

That brings us to the Supreme Court review of the 2004 Arizona law requiring proof of citizenship to register to vote.

This idea is apple pie, right? Nobody wants non-citizens voting. In fact, the Arizona Republican Party sent out a press release crowing about how GOP stalwart Tom Horne, Arizona’s attorney general and governor wanna-be, will argue in favor of the law. Quite a guy.

But nobody has demonstrated large-scale voting fraud. The biggest problem with elections is that too few people participate. Or as Berman put it: “If Hispanics were voting Republican, there would be no problem.”

The 9th U.S. Circuit Court of Appeals struck down part of Arizona’s voter-ID law because it was in conflict with the National Voter Registration Act. Arizona imposed a requirement to show proof of citizenship, but the federal form simply requires people to attest to their citizenship. The court said Arizona could not prohibit use of the federal form.

The federal law was designed to increase voter registration, in part, by “overriding burdensome state registration laws,” according to a brief filed by the League of Women Voters, which doesn’t like the voter-ID law.

The Inter-Tribal Council of Arizona challenged the law, saying many Native Americans on tribal lands do not have the required documents.

Filing separate briefs in support of the law were recalled state Sen. Russell Pearce — he identifies himself in his brief as the author of the voter-ID law and “numerous historic” laws designed to save Arizona from the “adverse effects of unlawfully present aliens” — and Kansas Secretary of State Kris Kobach, champion of the big-stick, attrition-through-enforcement approach.

With friends like these, you may not need history to cast a shadow on this law.

But history matters — especially when you have a party in power in state politics facing a growing population of people who traditionally vote for the other party.